Blade assembly

Abstract

An adjustable blade assembly for use in a rotary machine, such as a turbine or a compressor, wherein the airfoil is separable from the assembly at the blade platform. The airfoil is provided with a root which is seated within a complementary kerf formed within the platform. Each of the two sections is fabricated independently using standard machine tools, thereby eliminating the need of hand-forming, complex blade contours. In assembly, the airfoil is loosely supported within the platform whereby the stresses generated at resonant frequencies are highly damped.

What is claimed is: 
     
       1. An adjustable blade assembly for use in a rotary machine for processing a working fluid, said blade assembly including an airfoil and an independent airfoil support,   said support further including a platform of generally cylindrical form having a trunnion secured to one end face thereof, the support being pivotably mounted within a mounting ring with the opposite face of the platform being coextensive with one surface of said ring,   said opposite face of the platform having an aperture formed therein,   said airfoil being seatable upon said platform and having a root dependent therefrom which is loosely received in said aperture, and   means for preventing the airfoil from moving radially in reference to the platform when said airfoil root is positioned within said aperture.   
     
     
       2. The blade assembly of claim 1 further including a shank operatively associated with said trunnion, said shank extending beyond said ring and being engageable with means operable to pivot said blade assembly with said ring. 
     
     
       3. The blade assembly of claim 1 wherein said aperture is a rectangular kerf and said means for preventing the airfoil from moving radially comprises a pair of spring pins, each pin being arranged to engage one side wall of the kerf and one leg of the root when the blade is assembled.